Motor fuel composition



Sta es 2,991,162 i MOTOR um. COMPOSITION' Robert Malec, Chicago, 11]., assignor to Standard 0i] 7, Company, Chicago, 111., a corporationof Indiana .No Drawing. Filed'May 11, 1960, Ser. No. 28,245

19 Claims. (Cl. 44"'5-8) The present invention relates to an improved'motor fuel composition for spark-ignition internal combustion engines, and more particularly to such motor fuel compositions containing an additive which functions to inhibit or to reduce deposits in .the induction system of sparkignition internal combustion engines.

Rough idling and engine stalling requiring frequent carburetor adjustments and reconditioning have been prob- Patented July 4, 1961 of removing blow-by deposits' accumulated in the inducinduction; system of such engines, from about 0.00 05% to lems in certain kinds of automotive engine service.

These problems have been accentuated with increased traffic in congested areas and the use of multi-throat carburetors in private passenger cars. It has been determined that a primary factor in poor idling operation is an accumulation of deposits in the throttle body section of the carburetor which causes an over-rich mixture at idle and a reduction in idle speed. The accumulation of deposits in the induction system of the engine and particularly in the throttle section of the carburetor is particularly pro nounced in services requiring considerable idling such as taxicab anddoor-to-door delivery service. In private automobile operation, this problem is particularly empha sized in the metropolitanareas where heavy city traflic is encountered with appreciable stop-and-go driving.

The critical'accumulation point for these deposits is adjacent to the throttle plate, whose position controls thefuel ratio. As these deposits accumulate, the air flow at idle is restricted with no change in fuel flow, and a rich mixture results causing erratic idling and engine stalling. In order to compensate forthe presence of these deposits, the throttle must be opened slightly by increasing the idle speed adjustment which, although allowing more air flow, automatically supplies more fuel. This requires a fuel correction by changing the idle mixture adjustment screw a compensating amount. The amount of idle adjustment required to. maintaih satisfactory idle performance an indication of the rate of deposit build up. Furthermore; deposits will often form in the idle passageway causing restriction which allows manifold vacuum to draw. more gasoline into the engine, again causing rich idle and engin stalling.

'It has been established that the primary source of these deposits is the contaminants in the intake air of the engine when operatingiat idle. The greatest source of these intake air contaminants is engine blow by, which accounts for approximately one-half of the deposits; Exhaust from other vehicles, dust, and other components classed as normal air pollutants contribute to the formation of deposits. It is accordingly an object of the present invention to provide a motor fuel composition for spark-ignition internal combustion engines which will inhibit or alleviate deposits in the induction system of such engines. Another object of the invention is to provide a motor fuel composition for spark-ignition internal combustion engines which will prevent rough idling and stalling of such engines due to the accumulation of deposits in the induction system of such engines. Still another object of the invention is to provide a motor fuel composition which will remove deposits from the induction system of spark-ignition internal combustion engines. A further object of this invention is to provide an additive concentrate, which when added in small amounts to a motor fuel for spark ignition internal combustion engines will inhibit or re It is also an object of this invention to provide a method about 015% preferably from about 0.001% to about 0.01%, based on the hydrocarbon fuel, of a mixture con sisting essentially of (1) a hydroxy-alkyl 3-(N-a1kylamino)-propylc rbamate or hydroxyalkyl 3-(N-alkenyl amino)-propylcarbamate and (2) an N-alkyl or Nalkenyl substituted propylene urea in the ratio of from about 1:2

in which R is an acyclic aliphatic radical, i.e. an alkyl or alkyleneradical, having from about 8 to about 32 carbon atoms, and is preferably an alkyl group of from about 10 to about 20 carbon atoms derived from a fatty acid or mixed fatty acids, and R}, R R and R are hydrogen or an alkyl radical of from about 1 to about 4 carbon atoms.

a When R R R3 and R are ,alkyl radicals, they can be the same or diiferent alkyl radical.

Suitable areas are those having the general formula i" RN \NH Hz lfi CH, wherein R-is as above described, and can be the same or Examples of suitable carbamates are:

Suitable cyclic ureas are illustrated by the following examples:

13: H: C I N-dodeeylpropylene urea Cums-N a V \C 2 N-oieyl or N-ootadecenylpropylena urea o n-N NH 7 E2 4 11: C a

N-stearyl or N-octadecyl propylene urea While combinations of the described carbamates an cyclic ureas in the defined ratios. are efiectiveythey" are not all necessarily equivalent in their effectiveness, since the specific activity of such mixtures may vary to some extent depending upon the severity of conditions during use and other factors. 'In the preparation of the motor fuel compositiomthe carbamate and the urea can be added to the fuelindividually in the defined amounts and proportions, the carbamate and the urea can be pre-admixed in the desired ratio and the mixture added to the fuel, or the mixture ofcarbamate and urea prepared in situ can be added to the fuel. e

The mixture of carbamate and cyclic urea can be conveniently prepared in situ by reacting molar proportions To a refluxing mixture of 144 g. (0.5 mole) of N-coco- 1,3-propylene diamine and 187 g. of xylene was added 43 g. (0.49 mole) of ethylene carbonate over a 4 /2 hour period. The carbamate-urea ratio of the product was 8.2.

- EXAMPLE III To 144 g. (0.5 mole) of N-coco-1,3-propylene diamine was added 43 g. (0.49 mole) of ethylene carbonate over a four hour period during which time the temperature was maintained at 170 C. The carbamate-urea ratio of the product was 0.42.

of an N-alkyl or N-alkeny1-1,3-propylene diamine and al i. t.

wherein R, R R R and R are as above described.

The formation of the cyclic urea (H) a tetrahydropyrimidone, is a condensation reaction involving the splitting out from the 3-amino carbamate (1) a molecule of a glycol (HI) corresponding to the starting carbonate ester. The secondary reaction forming the cyclic urea is much slower than the initial reaction forming the carbamate, making it facile to vary the reaction conditions so as to obtain the desired carbamate-urea ratio. Increasing the reaction time and temperature favor greater urea formation at the expense of "the carbamate yield. Product distribution is readily determined by infrared spectroscopy and the reaction can be easily directed thereby. When the desired reaction mixture is reached, the reaction is halted by chilling by suitable means and and isopropylalcohol.

The above reaction is illustrated by the following examples wherein the given ratios are weight ratios:

EXAMPLE I To 287 g. (1.0 mole) of N-coco -l li propylene diamine EXAMPLE IV To 81 g. (0.25 mole) of N-oleyl-1,3-propylene diamine was added 19.8 g. (0.22 mole) of ethylene carbonate over a 1 /2 hour period with stirring and maintaining the temperature at 160 C. The carbamate-urea ratio of the product was 1.6.

. EXAMPLE V To 144 g. of N-coco-1,3-propylene diamine was added 1 39.6 g. (0.45'mole) of ethylene carbonate over a six hour EXAMPLE VI To 144 g. of N-coco-LS-propylene diamine was added 39.6 g. (0.45 mole) of ethylene carbonate with stirring over a 5 hour period at 200 C. The intermediate product weighed 179 g. To 135 g. of this material was added 100 ml. of mixed xylenes. The mixture was refluxed for EXAMPLE VII To 316 g. (1.1 mole) of N-coco-l,3-propylene diamine wasadded 88 g. (1.0 mole) of ethylene carbonate with stirring over a 3% hour period at 140 C. The mixture was heated for an additional 6% hours at the same temperature. The product had a carbamate-urea ratio of 1.5. V 4 EXAMPLE vm f T0150 g. (0.52 mole) of N-coco-LS-propylene diamine was added 51 g. (0.5 mole) of propylene carbonate over a hour period with stirring. The temperature was maintained at 150 C. The heating and stirring was continued for an additional 5 hours. The

' product had a carbamate-urea ratio of approximately 1.

.. obtained in a so-called Pontiac carburetor gum test RNHCH CH cH- NH- where R is derived from a mixture of fatty acids, ob-

tained from the hydrolysis of coconut oil, having 6-18 carbonatoms, which are predominately fatty acids of adding a suitable solvent such as by the addition of xylene I v and 14 carbon atoms' 'The effectiveness of the described carbamate-cyclic urea in preventing stalling due to carburetor deposits is demonstrated by the data in Table I. These data were conducted in the following manner:

; 1 .1957 Pontiac engine provided with a 4-barrel Roch.-

"'5 ester carburetor is used in m-aking the test- A vacuum" port for distributor spark advance is'provided 'iii 'tlie carburetor throat area, and is normally located in the atmospheric pressure area during idling. As deposits build upon the throttle bore, it is necessary to open the throttle valve more to provide the same air flow for the same r.p.m. When this is done; the vacuum port then is partially in the manifold vacuum area. At the start of the test the vacuum on the port is about 2 to 3 inches ofmercury. The failure point of the-test is considered reached when this vacuum increases about 8inches of mercury, i.e. when the port' vacuum reaches to ll inches of mercury. 7 To increase the severity of the test, allof the crankcase blow by andsome of the exhaust are admittedto the carburetor. Thetime required for the base fuel (control) to fail is" about hours, ite. the time required for the vacuum toinciease' 8 inches of mercury when using the control fuel. Dui-ingthe test the engine is operated on a three (3)' minute cycle of; 2.75 minutes at 500 rpm. idle and. 0.25 minuteat: 1600 r.p.m. with no load. Throttle opening and mixture adjustments are made every hour, if necessary, to maintain a 500 r.p.m; idle speed; 3 H I V The improvement factor is calculated by:

Time required for failure on fuel containing the additive rovement facto Time required, for failure on I r 4 base fuel The results of the test are expressed in terms of the improvement factor as above defined. The base motor fuel employed was a commercial premium gasoline containing the usual additives, i.e. tetraethyl lead, scavengers, antioxidant, metal deactivator, etc.

Table I -Fuel Improvement Factor Base F l No. 1+24 p.p.m. Product Example I No. 1+24 p.p.m. Product Example VII...-- No. 1+24 p.p.m. Product Example VIII.

oneoo .m a: mooaaco mo In addition to the above test data, gasoline compositions of the present invention were subjected to extensive tests in laboratory engines and in the field. In the laboratorygasolines' containing the -carbamate-urea mix ture of thisinvention passed-the'Chevrol'et induction system deposit; (ISD) test, theCFR L-head surface ignition test and the spark plug fouling test. Further, the de fined mixture demonstrated no deleterious effects on the initial, or storage stability of the base gasoline. Gasolines containing the defined carbamate-urea mixture were field tested in a fleet of taxi-cabs over an extended period of time with, periodic inspections of the induction. systems, particularly the carburetors of the test cabs. In this test it was observed that the test gasolines inhibited induction system deposits as well as effectively removed existing deposits. As a result the cabs operating on the test fuels gave continuous satisfactory service extending beyond periods when normally carburetor adjustments or overhauling was to be expected. Motor fuels containing the 'carbamate-urea mixture.

known antioxidants, stabilizers, anti-icing agents, antiknock'agents, scavenging agents and/or other additives which arecommo'nly employed in' motor fuels forsparle ignitio'n'internal combustion engines. 7' Percentages. given herein and in the appended claims are. weight percentages unless otherwise stated. 5

Iclaim: a

1. A motor fuel composition comprising a major proportion of a hydrocarbon base fuel distilling within the gasoline distillation range and'from about 0.0005% to about 0.5% of a mixture of 1) a carbamate selected from the group consisting of a hydroxyalkyl 3-(N-alkyl-' amino)- propylcarblamate and a hydroxyalkyl 3'-(-N-al-' kenylamino)-propylcarbamat e having the general formula in which R is an acyclic aliphatic hydrocarbon radical having from about 8 to'about 32 carbon atoms, and R R R and R are selected from the group consisting, of hydrogen, an alkyl radical of from about 1 to about 4 carbon atoms and mixtures thereof, and (2) a substituted propylene urea having the general formula I CH:

in which R is an acylic aliphatic hydrocarbons radical having from about-8 to about 32 carbon atoms, said carbamate and said cyclic urea being present in said mixture in the weight ratio of from about 2:1 to about 1 :2.

2. A motor fuel composition as described in claim 1 wherein R is an alkyl radical of from about 8 to about 18 carbon atoms derived from mixed fatty acids, and R R R and R are hydrogen.

3. A motor fuel composition to spark-ignition internal combustion engines comprising :a major amount of a hydrocarbon base fuel distilling within the gasoline distillation range, a tetra-alkyl lead anti-knock agent and from about 0.0005 to about 0.05% of a mixture of (1) a 2-hydroxyethyl 3-(N-alkylamino)-propylcarbamate having the general formula RNHOHiOHiCHiNHC iOGHQGHmH and (2) a substituted propylene urea having the general formula a a v o l RN \NH where R is an alkyl group of from about 8 to about 32 carbon atoms, said carbamate and said urea being present in said mixture in the weight ratio of from about 2:1 to about 1:2.

4. A motor fuel composition as described in claim 3 in which R is an alkyl group of from 8 to about 18 carbon atoms derived from coconut fatty acids, and in which said carbamate and said urea are present in said mixture in the weight ratio of about "1:1.

5. A motor fueljcomposition as described in claim 3'- in which the tetra alkyl lead anti-knock agent is tetra-v ethyl lead.

6. A motor fuel composition as described in claim 3 in herein described can contain in addition thereto 'well which R is an oleyl radical.

7. A motor fuel composition for spark-ignition internal combustion engines comprising a major amount of a hydrocarbon base fuel distilling within the gasoline distillation range, a tetraalkyl lead anti-knock agent and from about 0.0005 to about 0.05% of a mixture consisting of (1) a Z-hydroxypropyl S-(N-alkylamine) -propylcarbamate having the general formula RNHCHaCHnCHzNHil O CH( CH!) CHaOH and (2) a substituted propylene urea having the general formula where R is an alkyl group of from about 8 to about 32 carbon atoms, said carbamate and said urea being present in said mixture in the weight ratio of from about 2:1 to about 1:2.

8. A motor fuel composition as described in claim 7 in which R is an alkyl group of from 8 to about 18 carbon atoms derived from coconut fatty acids, and in which said carbamate and said urea are present in said mixture in the Weight ratio of about 1:1.

9. A motor fuel composition as described in claim 7 in which the tetra alkyl lead anti-knock agent is tetraethyl lead.

10. A motor fuel composition as described in claim 7 in which R is an oleyl radical.

11. An additive for use in small amounts in hydrocarbon fuels of the gasoline boiling range adapted for use in spark-ignition internal combustion engines to maintain the induction system of such engines essentially free of deposits, said additive consisting essentially of a mixture of (1) a carhamate selected from the group consisting of a hydroxyalkyl 3-(N-alkylamine)-propylcarbamate and a hydroxyalkyl 3-(N-alkenylamino) -propylcarbamate having the general formula R R RNHCH CH OH H o 2 2 rNHCO OH in 1's in which R is an acylic aliphatic hydrocarbon radical having from about 8 to about 32 carbon atoms, and R R R and R are selected from the group consisting of hydrogen, an alkyl radical of from about 1 to about 4 carbon atoms and mixtures thereof, and (2) a substituted propylene urea having the general formula II RNHCHaCHzCHzNHCOCHaCHaOH formula H113 Ha C a where R is an alkyl group of from about 8 to about 32 carbon atoms, said carbamate and said urea being present in said mixture in the weight ratio of fi'om about 2:1 to about 1:2. 7 v

13. An additive as described in claim 12 in which R is an alkyl group of from 8 to about 18 carbon atoms derived from coconut fatty acids, and in which said carbamate and said urea are present in said mixture in'the weight ratio of about 1:1. r I

14. An additive for use in small amounts in leaded gasoline for spark-ignition internal combustion engines to maintain the induction system of such engines essentially free of deposits, said additive consisting essentially of a mixture of (1) a 2-hydroxypropyl 3- (N-alkyla mino)- propylcarbamate having the general formula II nNnomomomNnooomoHo cmoH and (2) a substituted propylene urea having the general formula 15. An additive as described in claim 14 in which R is'an alkyl group of from 8 to about 18 carbon atoms derived from coconut fatty acids, and in which said car- 'bamate and said urea are present in said mixture in th weight ratio of about 1:1.

16. The method of preparing an additive for use in small amounts in hydrocarbon fuels of the gasoline boiling range adapted for use in spark-ignition internal combustion engines to maintain the induction system of such engines essentially free of deposits, which method comprises reacting molar proportions of a diamine having the general formula RNH(CI-I NH and an alkylene carbonate having the general formula at a temperature of from about 50 C. to about 250 C. for a time suflicient to give a reaction product consisting essentially of a mixture of a carbamate having the general formula R1 m aumomnmrcob-bon and a cyclic urea having the general formula ll RN NH in which R is an acyclic aliphatic hydrocarbonradical having from about 8 to about 32 carbon atoms,- and R R R and R are selected firom the group consisting of hydrogen, an alkyl radical of from about 1 to about 4 carbon atoms and mixtures thereof, said carbamate and said urea being present in said mixture in the weight ratio of from about 1:2 to about 2: 1.

17. The method of claim 16 wherein R is an alkyl radical of about 8 to about 18 carbon atoms derived from 1 18. The method of claim 16 in which the alkylene carbonate is ethylene carbonate.

19. The method of claim 16 in which the alkylene car- 'bon-ate is propylene carbonate.

References Cited in the file of this patent UNITED STATES PATENTS Lindstrom et a1. Jan. 26, 1960 Andress Nov. 22, 1960 UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent No. 2,991,162 July 4, 1%].

Robert E. Malec It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 6, line 34, for "hydrocarbons" read hydrocarbon column 7, lines 6 and 41, for "3(N-=alkylamine)", each occurrence, read 3-(N-alkylamino) column 8, line 36, after the formula, the following should be inserted:

where R is an alkyl group of from about 8'to about 32 carbon atoms, said carbamate and said urea being present in said mixture in the weight ratio of from about 2:1 to about 1:2.

Signed and sealed this 17th day of October 1961.

(SEAL) Attest;

ERNEST w. SWIDER DAVID n DD Attesting Officer Commissioner of Patents 

1. A MOTOR FUEL COMPOSITION COMPRISING A MAJOR PROPORTION OF A HYDROCARBON BASE FUEL DISTILLING WITHIN THE GASOLINE DISTILLATION RANGE AND FROM ABOUT 0.0005% TO ABOUT 0.5% OF A MIXTURE OF (1) A CARBAMATE SELECTED FROM THE GROUP CONSISTING OF A HYDROXYALKYL 3-(N-ALKYLAMINO)-PROPYLCARBAMATE AND A HYDROXYALKYL 3-(N-ALKENYLAMINO)-PROPYLACARBAMATE HAVING THE GENERAL FORMULA 